Method and a device in spindles

ABSTRACT

For carrying out a method to displace an object from a resting position to to a working position or vice verse, a device (1) is arranged comprising a screw (3) with two threads (7, 9) with different pitches and a body (2, 4) with internal threads matching the threads of screw (3). The body is shaped in two parts (2) and (4), which are arranged to be able to be displaced relative to one another in the axial direction of the screw (3), whereby a changing from one thread to another thread can be done by changing the distance between said parts (2, 4) of the body. The screw (3) is arranged to a first object and the body (2, 4) to a second object. In utilization of the method the object can be rapidly displaced to the resting position or working position by the fact that the screw and body are engaged with one another in the one thread or a coarse thread and when needed the screw and body are brought to change to an engagement with one another in the other thread or a fine thread, for example by an increased tightening force action.

BACKGROUND OF THE INVENTION

The present invention relates to a method in displacement of objects,for example in displacement of an object from a resting position to aworking position or vice verse, and in which method a device is arrangedcomprising a screw with at least two threads of different pitches andwhich screw is arranged in engagement with a body or with one or moreinternal and with the screw matching threads shown by the body. At thisthe screw is arranged to a first object and the body to a second object.In the method the first object and/or the second object is brought todisplace a distance when the screw and body are in engagement with oneanother in a first thread or for example a coarse thread and alsosubsequently when the screw and body are in engagement with one anotherin a second thread or for example a fine thread or vice verse.

In a great number of different situations there is a need to be able torapidly displace an object in a device or in a direction towards or froma device or a second object, for example in order to attain a quickengagement or a quick release action and removal of a device or anobject or other rapid movement. Often, it exists also a need to be ableto increase the tightening tension, as when clamping a device, amaterial, etc. In applicable cases there is also a need to be able toreduce that power, which is required to arrange an object in a workingposition or to remove the object from a working position, as in a manualhandling, for example when an object is clamped. In certain cases thereis also a need to attain a function of self-obstruction. Areas wheresuch a need exists are for example in clamping jaws, vices, pullertools, lifting jacks, various kinds of supporting legs, sliding valves,etc.

For carrying out a method it is required a device. In known devices inquestion one has been forced to compromise between good tension ortightening force action and high speed of the displacement. Thus, onehas got a low tension in designs with rapid displacement of objects. Onehas got a slower displacement of objects in designs with improvedtension. With regard to this it would be advantageous if one was able tomake a rapid displacement of objects when none or low tension ortightening force action is needed and in cases when tension or hightension is needed be able to have the device to work with high tension.

In for example a supporting stand with a land wheel for a trailer, thestand is arranged releaseable from a folding position and shows a screwwith a thread with a small pitch. At this the supporting stand can bedropped so that the land wheel will be situated close to a foundation,after which the vehicle or its chassis can be raised by rotating thescrew. The rotation of the screw can be effected by manual power as thescrew has a small pitch and the screw will also be self-obstructed. Ofcourse, such a supporting stand can instead for being able to fold bearranged only vertically adjustable by rotation of the screw. In such acase the screw must, however, be rotated a great many revolutions toreach a working position and a resting or storing position respectively,which is i.a. time-consuming.

A previously known device which, however, has not been used inconnection with supporting stands, shows a screw with two threads withdifferent pitches and a nut, which is arranged with the screw withmatching threads. By a radial turn of a part of the nut, an angulardisplacement of the threads is effected in said part in relation to thethreads in the remaining part of the nut, whereby the nut can changefrom a first thread to a second thread of the screw. Such a method has,however, certain limitations, as it requires a manual handling and aturning of a part in a device in order to be able to carry out themethod. The fields of application are further restricted for the methodby the shaping and way of operation of the device. In addition, it hasbeen shown difficult to carry out intended methods due to the shaping ofthe changing devices. The function of the screw and/or the nut has notbeen satisfactory. Further, the method is impossible to utilized in suchoccasions when the device for carrying out the method must be containedwithin a limited or small space.

SUMMARY OF THE INVENTION

The purpose of the present invention is to achieve a method where adisplacement of an object can be done in a rapid way until the objectreaches a working position. In applicable cases, in the working positionshall the necessary power, which is needed to complete the method, be solow that the method can be carried out manually but still withsufficient or intended tension or tightening force action whennecessary. A release of the object from the working position shall,where appropriate, also be able to be done manually as well as a rapidmovement of the object to a resting or storing position. Further, thedevice used for the realizing of the method shall not need to bemanually handled for a changing between different threads or a rapidmovement or a slower transportation with improved tension. Utilizationof the device shall mean an automatic function. When an improved tensionor tightening force action is needed, it shall be able to be realized ina method for rapid movement of objects. A supporting stand for vehiclesshall in a rapid way be able to be screwed to a working position, i.e.into touch with a foundation, from a removed and screwed-up position,which is done by rapid movement of the supporting stand in a thread ofthe screw with large pitch. The supporting stand changes automaticallyin the working position to another thread of the screw with a smallpitch, whereby the intended tightening force action is attained and thatthe screw still can be easily rotated despite the loading of thevehicle. When the supporting stand again shall be moved to the removedand screwed-up position a changing to the first thread andtransportation of the supporting stand is done inversely. In applicablecases it can be considered necessary to be able to secure the taken upand self-obstructed position between supporting stand and screw andtherefore it ought to exists in said case a possibility for a lockingoperation. Said locking ought to operate automatically. A method inaccordance with the invention has obtained the characteristics mentionedin claim 1.

The invention also relates to a device for carrying out the method. Thedevice comprises hereby a screw or a spindle with a screw or spindlebody with at least two threads with different pitches. The screw isarranged in engagement with a body or with one or more internal and withthe screw matching threads or similar shown by the body. The device ischaracterized in that the said body consists of two bodies or nuts,which are arranged non-turnable with each other but axially displaceablewith one another via the engagement with threads of the screw. Thedevice can change from a first thread to a second thread or vice verseby changing the distance between the both bodies.

According to an embodiment of the device in accordance with theinvention, the device comprises a load sensing device, whereby such adevice is arranged in the both bodies and arranged to be able to belocated with a part in one thread of the screw and be able to be broughtout from the thread of the screw when a load arises.

In another embodiment of the device in accordance with the invention,the device comprises a locking device, which is arranged to hold bothbodies in an occupied, relative, axially position or in a position wherethe bodies bear on each other. It is hereby ensured that the screw andbodies maintain a relative position with one another in a thread.

According to an additional embodiment of the device in accordance withthe invention, the screw is arranged to a vehichle or a trailer, such asa trailer for a car, a caravan, or a chassis, a draw beam or a couplingdevice for such vehicles, and the body or bodies are arranged to asupporting stand for such vehicles. The supporting stand can hereby beprovided with a land wheel.

In a device in accordance with the invention, the risk of operationsbeing interrupted due to the device is substantially reduced orcompletely eliminated. Furthermore, the device is easily adapted tomultiplicity of applications within widely differing fields.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics of and advantages with the method and device inaccordance with the invention will be apparent in the followingdescription of the invention by embodiment examples, whereby asimultaneous reference will be made to the accompanying schematicdrawings, of which FIG. 1 shows from one side an embodiment of a screw,FIG. 2 shows from one side a portion of a screw body, FIG. 3 shows in anenlarged scale a part of a screw, FIG. 4 shows partially in section abody according to one embodiment, FIG. 5 shows in cross-section a bodyaccording to a second embodiment, FIG. 6 shows from one side andpartially in section a portion of a supporting stand and a part of adriving device connected with a device in accordance with the inventionand according to one embodiment, FIGS. 7-10 shows from one side andpartially in section examples of a working process for a device inaccordance with the invention according to one embodiment example, FIGS.11-14 shows from one side and partially in section a portion of asupporting stand with a device in accordance with the inventionaccording to another embodiment, FIGS. 15-17 shows from one side andpartially in section a portion of a supporting stand and a part of adevice according to FIG. 6 and in different positions, FIG. 18 showsfrom one side and in cross-section a part of a supporting stand, FIG. 19shows from one side two bodies according to a third embodiment and apart of a device in accordance with the invention according to a thirdembodiment and which device can form a device in the supporting standaccording to FIG. 6 and FIGS. 15-17. FIG. 20 is a sectional view takenon plane 20--20 in FIG. 19, FIG. 21 shows the opposite side of thedevice, FIG. 22 is a sectional view taken on plane 22--22 in FIG. 19.FIG. 23 shows the device according to FIGS. 19-22 from below, FIG. 24shows from one side a holder, which can become part of a device inaccordance with the invention, FIG. 25 from one side a mow able wedge,which can become part of a device in accordance with the invention, FIG.26 shows from one side and partially in section a portion of asupporting stand or the supporting stand according to FIG. 6 and in anupper position, FIG. 27 shows in cross-section two bodies according to athird embodiment, whereby the bodies have taken a second position, FIG.28 shows from one side a wedge according to a second embodiment and FIG.29 shows from one side a guiding means and a holder according to asecond embodiment and a holder for the wedge according to FIG. 28.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The reference designation 1 in FIGS. 6-17 and 26 shows parts of a deviceand in certain cases according to different embodiments. A device 1 inaccordance with the invention comprises a screw 3 with a spindle body 5,see FIGS. 1-3, and a body 2, 4 or shaped as a first or lower body 2 anda second or upper body 4, see FIGS. 4, 5 and 27. The bodies 2, 4, whichare in the form of nuts suited to the screw 3, are preferably providedwith at least one controlling device in the form of a load sensingdevice 18.

The spindel body 5 of the screw 3 shows one or more threads 7, 9 or,according to the embodiment example, two threads, for example a firstthread 7 or coarse thread and a second thread 9 or fine thread, wherebythe threads have different thread pitches. Each of the threads 7, 9 arearranged in a separate spiral path 11 and 13 respectively along thespindle body 5. Thus, a spindle or a spindle body can be provided with afine thread 9. Then the fine thread 9 can be eliminated in a spiral 11extending helically around the spindle body, whereby the remaining finethread 9 forms a second threaded helical spiral 13 with severalentrances, while the first spiral 11 forms a spiral path or a groove,which does not have threads or substantially have any threads. In thisway the first thread 7 or the coarse thread will divide the fine thread9, which accordingly will have or can show a number of individualthreads which, where appropriate, extend only over a part of theperiphery of the spindle body 5. Preferably the first thread 7 is givena substantially larger pitch 18 than the individual threads in thesecond thread 9.

One end of the screw 3 can show an attachment portion 19 with anengagement device 21, for example in form of a hole for the attachmentwith an object or a driving device. A contact device 23, bearing,divider or the like can be arranged between the spindle body 5 or thethreads 7, 9 and the attachment portion 19.

The said first thread 7 or coarse thread can show or be shaped with agroove 15 for a part 20 of a load sensing device 18 or a controllingdevice, for example in form of a ball or a so-called pilot ball, whichis indicated in FIG. 3. On the side of the groove 15 exists surfaces 17against the flanks of adjacent other threads 9 or fine threads.

The said body 2, 4 or both bodies show one or more internal threads 6, 8or similar, matching respectively the threads 7, 9 of the screw 3, i.e.in accordance with the embodiment examples two threads with differentpitches, as fine threads 8, which are arranged in a spiral 10. Thus, thebodies 2, 4 can be provided with a fine thread 8 which then beingeliminated in a spiral 12 which, thus, will not have any threads. Inthis way the remaining fine thread 8 forms a spiral 10 with threads 8with several entrances. The fine threads 8 in the threaded spiral 10together form a coarse thread 6, i.e. that the threaded spiral 10 existsin the first thread 7 or coarse thread of screw 3, when screw 3 isarranged to run in the bodies 2, 4 or vice verse with an engagementbetween the screw and bodies in a first thread 7, 6 or a coarse thread.The fine threads 9 of screw 3 or threaded spiral path 13 exist hereby inthe said spiral 12 of bodies 2, 4, which is in the form of a nonthreaded portion. When screw 3 is arranged to run in bodies 2, 4 or viceverse with an engagement between the screw and bodies in a second thread9, 8 or a fine thread, at least some of the fine threads 7 of screw 3are engaged with at least some of the individual fine threads 8 ofbodies 2, 4.

As previously has been mentioned and according to the embodimentexamples, there exist load sensing devices 18 in the bodies 2, 4 or oneor more load sensing devices 18 in each body 2, 4. In order to bear theload sensing devices 18, the bodies 2, 4 show first openings 14 in formof holes, which extend through the bodies to that axially extendinghole, which extends through the bodies for receiving the screw 3. In theembodiment in FIG. 5 there exists two openings 14, each opening arrangedfor a load sensing device 18 or a controlling device 20. In theembodiment in FIG. 27 there exists three openings 14, each openingarranged for a load sensing device 18 or a controlling device 20, as hasbeen indicated, whereby one attains a more uniform division of the loadsensing devices 18 and a more uniform loading on the spindle 5 and therisk is avoided that a body 2, 4 is going to tilt because of unbalancedloading. According to the embodiment examples the load sensing devices18 form or comprise a controlling device 20 in the shape of a ball or aso-called pilot ball, which is elastically prestressed by a spring 22,for example a spiral spring. Further, the load sensing devices 18 arearranged in the middle of the threaded spiral 10 for the fine thread 8or fine threads.

In FIG. 6 is shown a device 1 in accordance with the invention in formof a supporting device 30 with a supporting stand 35 for a vehicle,which is one of multiplicity of areas of use for a device in accordancewith the invention. The vehicle can consist of various trailers, such asa trailer for a car, a caravan or a chassis, a draw beam or a couplingdevice for such vehicles, etc. The screw 3 is hereby arranged to a firstobject 31 or according to the embodiment example a chassis, a draw beamor a coupling device and can be driven by a driving device 33, as amotor, electric motor, manually by means of a crank 33, a handle or thelike, as is shown in the figure, etc. and is attached with the screw'sattachment portion 19 or its engagement device 21. A casing 34 can bearranged around the device 1 and the supporting stand 35. Besides thefact that the driving device 33 or the crank, etc. drives or rotates thescrew 3, the driving device 33 or the crank, the screw 3 and the casing34 are fixed and attached to the first object 31. When the screw 3 isturned or rotated in one way or the other by the driving device 33, theother object 32, consisting of the supporting stand 35, is displaceddownwards and upwards respectively. The supporting stand 35 can beshaped as a pillar, tube or similar and in the end be provided with asupporting plate, supporting wheel or the like. When the supportingstand 35 or its supporting wheel or the like reaches a foundation, asground, a floor, etc. the supporting stand stops, while the bodies 2, 4continue to move downwards as the turning of the screw 3 is proceeded,whereby the first, lower body 2 soon is going to strike a load 37,according to the embodiment example a shoulder 36 in the supportingstand 35, and when the body 2 reaches the load 37 or the shoulder 36 theload influences the load sensing device 18 or the means in the body 2.The other, upper body 4 continues to move downwards until the bodyreaches the first, lower body 2, whereby the second body 4 also hasreached a load, which influences the load sensing device 18 or the meansin the body 4.

Device 1 in accordance with the invention is arranged to be able toeffect at least two different displacements of screw 3 and/or one ormore bodies 2, 4 or objects 31, 32 connected with the screw or body orbodies or according to the embodiment example an object 32 in order toeffect a rapid transport of a supporting stand 35. Accordingly it is aquestion of device 1 being able to change between at least two differentdisplacements, whereby this change preferably can be carried outautomatically. Thus, device 1 comprises at least one load sensing device18 which can be arranged to sense if a body 2, 4 or an object 31, 32obtains a resistance, a load 2, 4, 36, 37, 61 or similar. For thatreason the bodies 2, 4 are displaceable with one another in the axialdirection of screw by the threads 7, 9 of screw 3.

With further reference to FIGS. 7-10 the function of the device 1 willbe described and accordingly also the exemplified supporting device 30or supporting stand 35 and the priciple for displacement of objects 31,32, whereby a simultaneous reference will be made to FIGS. 11-14 and15-17. Thus, it is evident that when the bodies 2, 4 or their coarsethread 6 run in the coarse thread 7 of screw 3, bodies 2, 4 are arrangedat a distance 24 from one another and take up a first axial position 41with one another. When the bodies 2, 4 or an object 32, which isconnected with the body or bodies 2, 4, for example a supporting stand35, or the screw 3 are displaced in a direction 43, see FIG. 7, a rapiddisplacement is done in coarse thread 7 of screw 3. Correspondingconditions are shown in the embodiments in FIGS. 11 and 15. It should bepossible to say that device 1 is in a transporting position. When thefirst or lower body 2 or the said second object 32 or the supportingstand 35 gets or reaches a resistance or a load 36, 37 or the first body2 according to the example reaches the shoulder 36 the load is sensed bythe load sensing device 18 in the first body 2 by the fact that an axialloading is obtained on body when it strikes against the shoulder 36,whereby the first body 2 climbs the second thread 9 or fine thread ofscrew 3, i.e. the fine threads 8 or individual fine threads 8 of body 2begin to enter adjacent fine threads 9 or threaded spiral 13 of screw 3.The second body 4 is still displaced in the first thread 7 or coarsethread of screw 3, see FIG. 8, until the second body 4 reaches the firstbody 2, see FIG. 9, whereby the second body 4 obtains a resistance or aload 2, 37 from the first body 2, which is sensed by a load sensingdevice 18 in the second body 4 by an axial loading on the body when itstrikes the first body 2. In this connection the second body 4 alsobegins to climb the second thread 9 or fine thread of screw 3, etc., ashas been described above in connection with the first body 2. When thesecond body 4 is engaged with the second thread 9 or fine thread ofscrew 3, i.e. when the individual threads 8 of the bodies 2, 4 are inengagement with the fine threads 9 of screw 3, the change from a firstthread or coarse thread is carried out, see FIG. 10. Bodies 2, 4 ortheir threads 8 are now running in the fine thread 9 of screw 3 and thebodies 2, 4 are no longer situated at a distance from one another buttake up a second axial position 42 with one another, see also FIGS. 13and 17. The direction of turning or rotation of screw 3 is shown witharrows 38 in FIGS. 7-10.

When the resistance, load 2, 4, 36, 37 or similar reduces or ceases, thebodies 2, 4 or their threads 8 or fine threads 8 return to the firstthread 7 or coarse thread of screw 3 in the reverse way, i.e. beginningwith the second body 4, whereby a change occurs again.

The load sensing devices 18 are arranged in each body 2, 4 and accordingto the example comprise a controlling device 20, for example in theshape of a ball or a so-called pilot ball and a spring 22, which isarranged to hold the controlling device 20 against a base, which is thecoarse thread 7 of screw 3 or the groove 15 in the coarse thread 7 orvia the surfaces 17 to a contact position against the fine threads 9 orthreaded spiral 13 of screw 3, when the body or bodies 2, 4 aretransferred to the second position 42 and when they have taken up thesecond position 42. Against the action of spring 22, the controllingdevice 20 can be permitted to follow elevations in the base or screw 3.

According to the embodiment example in FIGS. 7-10, whereby thecorresponding can be valid for the embodiments according for exampleFIGS. 11-14 and FIGS. 15-17, the load sensing device 18 controls or runsby means of a pilot ball 20 in the first thread 7 or coarse thread ofscrew 3 the displacement of the bodies 2, 4 during the rotation of screw3 or vice verse.

Thus, the power exists on the balls 20. When a body 2, 4 is to climb afine thread 9 of screw 3, the pilot ball 20 is pressed against theaction of the spring 22 from the coarse thread 7 for contact against thefine thread 9, i.e. the pilot ball 20 is moved aside into the said firstopening 14 and out of its controlling engagement with coarse thread 7.The bodies 2, 4 are thus mechanically operated by means of the loadsensing device 18 or pilot ball 20 in the coarse thread 7 of screw 3until a body 2, 4 or bodies reach a resistance, load 2, 4, 36, 37, 61 orsimilar, whereby when the load exceeds the limit load of pilot ball, thepilot ball is moved out of its controlling position and ceases themechanical operation of the body 2, 4. It can be possible to say thatthe balls 20 form a supplying device, when an axial force is directedagainst the bodies 2, 4. The distance 24 between the bodies 2, 4, whenthe bodies are displaced in the first thread 7 or coarse thread of screw3, is a coarse thread pitch.

The shown and described embodiment examples have referred to screws 3and bodies 2, 4 with screw threads or similar with a change-over betweendifferent thread pitches, and even an automatic one. Such an automaticchange-over can also be attained with so-called ball screws, when thescrew 3 also shows at least two threads 7, 9 with different threadpitches or corresponding ball paths, while the bodies 2, 4 should show aball path. When using a device 1 some form of resilient, load sensingwork is usually carried out which, at a predetermined axial loadingbetween screw 3 and bodies 2, 4 permits the bodies in turn to changefrom the one or a first thread and a second thread. When low loadingagain occurs the change is carried out in reverse. The bodies 2, 4 arenot allowed to Change at the same time, whereby at least one of thebodies in a position is separated from the changing points. In this waythe screw 3 can always bear a load, which corresponds to what a body canbear. However, the bodies 2, 4 must be able to move relatively to eachother so that when changing take place they displace in differentpitches, whereby the relative movement between the bodies is carried outunder the angle of rotation of screw 3, as the changing is under way.According to one embodiment of device 1 in accordance with the inventionor according to the embodiment examples, the said relative movementbetween the bodies 2, 4 is arranged to be carried out in the axialdirection of screw 3, i.e. it is an axial movement. It should at leastin other objects and displacements also be able to be a rotation or acombination of an axial movement and rotating.

The bodies 2, 4 are rotation-locked in relation to each other orarranged non-turnable with one another, which can be effected by adevice, as a guiding means 25 which, according to the embodimentexamples shown, is fixed arranged in the second, upper body 4 and runsin a slot 26 or groove in the bodies 2, 4 and shows in one end a stop orlimiting means 27 for the bodies 2, 4 in order to limit the distance 24between the bodies 2, 4.

With further reference to FIG. 18 it is shown a part of a second object32 which, according to the embodiment example, consists of a supportingstand 35, in the upper part of which a device 1 in accordance with theinvention can be arranged, whereby the shoulder 36 forms a stop and aresistance or a load 37 for the first body 2. Further, the stand 35shows a first guiding and limiting device 39 with an upper strikingsurface, which guides and limits the movement of a locking device 44.

In FIG. 24 is shown a holder 45 for a movable wedge 46, see FIG. 25, andfor a locking element 40. The holder 45 is shaped as a fork, i.e. with arecess 47, for receiving the movable wedge 46 and also shaped with alocking element 48, for example in the shape of a hole through theholder, for the locking element 40, which in the shape of a ball orsimilar shows a diameter, which exceeds the thickness of the holder,i.e. the ball can reach through the holder 45 and enter into a body 2, 4or, according to the embodiment examples, the second, upper body 4 orinto a seat for the locking element 40, which seat is shown by the body.According to the embodiment examples, the holder 45 shall be fixedarranged to the first, lower body 2.

The movable wedge 46 shows a protruding arm 49 with a wedge-shaped endportion 50, which shall be arranged to be able to reach outside and/orbeyond the recess 47 of the holder 45 and in one position be able toreach in front of and/or beyond the holding element 48 of the holder 45.One part 51 of the movable wedge 46 is arranged to be able to be locatedin the recess 47 of the holder 45 and can show a tapering end portion52, for example a spherical end portion, an end portion in the shape ofa cone or a double-wedge. Further, the movable wedge 46 shows a holdingmeans 53 for a second guiding or limiting device 54, for example in theshape of a threaded pin.

In FIGS. 19-23 is shown an example of a shaping of a part of the device1 and the bodies 2, 4, whereby it appears that the device 1 can comprisea locking device 44, see FIG. 20, and that the load sensing device 18can be kept in the device by holding devices 28 in form of for examplesprings of thin sheet-metal, which are held by pegs 29 or the like, seeFIGS. 19 and 22. It appears from FIGS. 20 and 21 i.a. the holder 45 forthe movable wedge and that the movable wedge rests on an elastic element57. In order to limit the movement of the movable wedge 46, a lower stop58 can be arranged. This stop 58 can consist of a tap or similar, whichrests on or is arranged in a bottom or supporting element 56, see alsoFIG. 23. Said element 56, which can show a shape of substantially an U,forms a bottom element or a supporting element for elastic element 57and also a holding means for stop 58 and is, as the holder 45, fixedarranged to first, lower body 2, for example by welding to the body 2.It appears also from FIG. 23 the slot 26 or the groove in the body 2, 4for the guiding means 25.

The load sensing devices 18 can instead be kept in the device 1 bysealing devices furnished to the openings 14, which sealing devices, forexample, can consist of rounds, which are driven in the end part of theopenings 14 or in another way are attached into the openings and sealthe openings and hold the pilot ball 20 or the controlling device inintended position with a spring 22 situated in between.

According to the embodiment examples, the locking device 44 is meant forbeing a locking mechanism, which locks screw 3 and bodies 2, 4 in theirengagement or position in the fine thread 9 or in other words locks thebodies 2, 4 to a maintained connection to each other, i.e. keep thebodies 2, 4 in a taken, second position 42. The locking device 44comprises, according to embodiment examples above, the holder 45, themovable wedge 46, the locking element 40, the elastic element 57 and aseat in a body 2, 4 which, according to the embodiment examples,consists of the said second opening 16 in the second, upper body 4. Thefirst and second guiding or limiting devices 39 and 54 respectivelycontributes in guiding of the locking device 44 and limiting the movmentof the movable wedge 46.

With reference to especially the embodiment in FIGS. 11-14 but also tothe embodiment in FIGS. 15-17, it is shown in FIGS. 11 and 15 that thedevice 1 and the bodies 2, 4 are in a first position 41, whereby coarsethreads 7 and 6 of the screw 3 and bodies 2, 4 respectively are inengagement with one another and that the load sensing device 18controlls, supplies and drives with the controlling device 20 in thecoarse thread 7 or its groove 15 of screw 3. The locking device 44 isnot in engagement with the second opening 16 or seat in the body 4, i.e.is in an inactive position. The supporting stand 35 is suspended and thebodies 2, 4 or the lower body 2 being at a distance from the shoulder 36or the load. The movable wedge 46 is kept in the inactive position bythe fact that an engagement part 55 of the wedge or that the secondguiding or limiting device 54 is arranged to project in engagement withthe first guiding or limiting device 39 shown by the supporting stand35, whereby, when the supporting stand is suspended in the air, thesupporting stand can with its weight or loading on the engagement part55 hold the movable wedge 46 in a pressed down position against theaction of elastic element 57. The direction of the power is shown byarrow 59 in FIG. 15. In rotation of screw 3 a rapidly displacement ofthe supporting stand 35 towards a foundation is done. When thesupporting stand 35 reaches the foundation, as it is shown in FIGS. 12and 16, the power will change direction, which is shown by arrow 60 inFIG. 16, but the bodies 2, 4 will continue their displacement until thatthe lower body 2 reaches the shoulder 36, i.e. reaches a load 37, whichalso appears from FIG. 12, whereby a power is built up against the lowerbody 2, which change to the fine thread 9 of screw 3. When thesupporting stand 35 does not displace further downwards the loading fromthe supporting stand 35 on the locking device 44 will cease, whereby themovable wedge 46 by the elastic element 57 will be displaced upwards.This is shown in FIG. 12 by the fact that the engagement part 55 leavesthe upper end surface in the first guiding or limiting device 39 in thesupporting stand 35. When the load 36, 37 exceeds the limit load of theload sensing device 18 or the controlling device 20, the lower body 2begins with its fine thread 8 or fine threads to climb the fine thread 9of screw 3, see FIG. 12. The controlling device 20 is prestressed by thespring 22 and when the controlling device 20 receives a power from thegroove 15 and the surface 17 in the coarse thread 7 of the screw 3 andthen by the fine thread 9 of the screw 3, the controlling device 20 ispressed into the first opening 14 against the action of spring 22. Thefine threads 8 of the lower body 2 and the fine thread 9 of screw 3 canengage with one another. The upper body 4 will soon reach the lower body2 and obtains a resistance or a load 37 of the lower body 2, whereby theupper body 4 begins with its fine thread 8 to climb the fine thread 9 ofscrew 3 in conformity with what has been described for the lower body 2.It appears from FIGS. 13 and 17 that the changing is carried out in thedevice 1 for the bodies 2, 4 in that the bodies have changed from thefirst thread or coarse thread to a second thread 9 or fine thread ofscrew 3, whereby the second position 42 is attained and the bodies 2, 4lie against each other. By the engagement of screw 3 and bodies 2, 4with one another in a fine thread, there exists a function ofself-obstruction. The movable wedge 46 is kept by the elastic element 57in an upwards displaced position in the device 1, i.e. the engagementpart 55 lie against the upper end surface of the first guiding orlimiting device 39 which, thus, prevents the movable wedge 46 from beingdisplaced further upwards in the device 1. When the upper body 4 hasreached and lie against the lower body 2 has, according to theembodiment examples, the locking device 44 taken up a position, in whichit can be active, i.e. the second opening 16 in the upper body 4, whichforms a seat for the locking element 40, is now in front of the lockingelement 40 by the continued displacement of the body simultaneously asthe movable wedge 46 has been displaced upwards by the elastic element57. Thus, the movable wedge 46 has been displaced in the recess 47 ofthe holder 45 and the protruding arm 49 with the wedge-shaped endportion 50 has by the displacement forced the locking element 40 againstthe seat in the second opening 16 in the upper body 4. The both bodies2, 4 have by that been locked against a relative unintentional axialdisplacement and that independent of the direction of rotation of screw3. The active locking position for the locking device 44 is apparentfrom FIGS. 13 and 17. The locking is active as long as load exists andlocking engagement of the locking element 40 is secured by the elasticelement 57, which holds the movable wedge 46 in the upwards displacedposition. The object or objects 31, 32 can now be displaced undertightening force action, as screw 3 and bodies 2, 4 are in engagementwith one another in the fine thread. When the load 37 changes directionand when the bodies 2, 4 in the locked position with each other aredisplaced upwards in the device 1 or from the shoulder 36, thesupporting stand 35 will force or press the movable wedge 46 downwards,which by that ceases to hold locking element 40 in the locking position,see FIG. 14. The locking element 40 can hereby move out of the saidsecond opening 16 or seat and a changing back to the coarse thread canbe done by the fact that the bodies 2, 4 again can move relative to eachother in axial direction and be separated from the contact against eachother. The rechanging is done in the reverse way, i.e. the second, upperbody 4 leaves the engagement in the fine thread and climbs the coarsethread and then also the first, lower body 2. The objects 31, 32 or thesecond object 32 or the supporting stand 35 can hereby again bedisplaced in a first thread or coarse thread for rapid movement.

It has been shown in tests with certain objects where a device 1 inaccordance with the invention has been used that it can exist a riskthat at least one of the bodies 2, 4 in the bodies 2, 4 engagement withand position in the fine thread unintentional can leave fine thread orjump back to an engagement with first thread or coarse thread which,especially when a large loading exists, can involve inconveniences. Suchpossible arising problems can be eliminated with the locking device 44.In for example a supporting device 30 with supporting stands 35, such anunintentional rechanging could happen when screw 3 by mistake will berotated the other way while device 1 is under tightening force action byengagement in fine thread and hole loading exists on the supportingstand. Such a possible unintentional rechanging is prevented by alocking device 44 in accordance with the invention, which locking devicethus forces the bodies 2, 4 in position with fine thread.

In FIG. 26 is shown that the supporting device 30 and the supportingstand 35 are raised or screwed up to an upper end position, i.e. thesupporting stand 35 suspends and freely from contact with a foundation.When the second, upper body 4 obtains a resistance or a load 37,according to the embodiment by a means 61, which consists of an o-ring,the body 4 changes to an engagement with fine thread by the axial loadfrom means 61. When the first, lower body 2 reaches the upper body 4 andobtains a resistance or a load 4, 37 of the upper body 4, the lower body2 also changes to an engagement with fine thread by the axial load fromthe upper body 4. The device 1 or the bodies 2, 4 can by the engagementin fine thread be displaced with an improved tension or tightening forceaction and to compressing or further compressing of the means 61 betweenthe upper body 4 and the contact device 23 and is self-constructed. Bythe existence of the self-construction and when no hevier loading existson the second object 32 or the supporting stand 35, there is no need forlocking the bodies 2, 4 in fine thread, i.e. the locking device 44 doesnot need to be activated even if the locking element 40 is in positionin front of the said second opening 16 or seat by the fact that thebodies 2, 4 are connected with or bear on each other. Besides, there issome frictional locking with the means 61. The movable wedge 46 is heldin a pressed down position and the arm 49 of the movable wedge 46 doesnot reach the locking element 40 to activate the locking element 44 andbring the locking element 40 into an engagement with the upper body 4 bythe fact that the movable wedge 46 or its engagement part 55 is inengagement with the supporting stand 35 or its first guiding or limitingdevice 39 or by the fact that the supporting stand 35 with the upper endsurface in the first guiding or limiting device 39 bear on theengagement part 55. With reference designation 62 is shown a bearing,which can be arranged between the objects 31, 32 or between the contactdevice 23 and the casing 34.

In FIG. 28 is shown an alternative shaping of a wedge 64, which forms apart of the locking device 44 but is fixed anchored in the device 1contrary of the other, previously mentioned movable wedge 46. The wedge64 shows in conformity with the other wedge a protruding arm 49 with awedge-shaped end portion 50 and a holding means 53, for example in formof a hole 63 through the wedge 64 for anchoring of the wedge to a body2, 4 or, according to the embodiment examples, the first, lower body 2by a anchoring device, as a screw. The wedge 64 shall not be providedwith a second guiding or limiting device 54 and can also be without thetapering end portion 52. As the wedge is fixed to the locking device 44it is allowed a simpler shaping of device 1 and locking device 44.

According to a previous embodiment there exists in the device 1 aguiding means 25, i.a. in order to hold the bodies 2, 4 non-turnablewith one another and a holder 45 for the wedge or the movable wedge 46and a locking element 40. In an embodiment of the device 1 in accordancewith the invention, the said guiding means 25 and holder 45 can beshaped in one and the same part and forms a holder for the lockingelement 40 and together with the wedge 64, which is fixed anchored, andthe locking element 40 form in the view of construction and design asubstantially simplified locking device 44 and at the same time a stopor limiting means 27, 67 for the bodies 2, 4. The wedge 64 is fixedanchored in a body 2. Thus, in FIG. 29 is shown a guiding means 70according to a second embodiment, which guiding means accordingly canreplace the other, previous guiding device 25 and the stop or limitingmeans 27 and also the other, previous holder 45, whereby only a slot 26or groove in the bodies 2, 4 is needed for receiving the guiding means25 and the holder 45, i.e. the guiding means 70.

In conformity with the description of the alternative shaped wedge 64,it is going to be used in description of the guiding means 70, whereappropriate, corresponding reference designations as in the descriptionof the other, previous guiding means 25 and movable wedge 46 for suchparts having corresponding or principally corresponding function. A slot26 or groove is arranged in the bodies 2, 4, whereby in the directiontowards the slot is arranged protruding edges or flanges. According tothe embodiment examples, the guiding means 70 is shaped with a waist 65or recess matching the said edge in the first, lower body 2 and a widerwaist 66 or recess for the said edge in the second, upper body 4. Owingto this, the guiding means 70 can be fitted into the slot 26 and be heldin the device 1 by the engagement of the said edge in the first, lowerbody 2 with the narrower waist 65. The second, upper body 4 can bedisplaced axially in the device 1 between the first position 41 andsecond position 42 by the fact that the wider waist 66 shows asufficient width. A lower end edge 68 in the waist 66 may not preventthe bodies 2, 4 from the possibility to take the second position 42 anddoes not either be needed to form a stop or contact means for thesecond, upper body 4, as the second, upper body shall be able to connectwith and can make contact against the first, lower body. On the otherhand can an upper end edge 69 in the waist 66 form a stop 67 or acontact means for the second, upper body 4 or the said edge in the slot26 in order to limit the distance 24 between the bodies 2, 4, when thedevice 1 or bodies 2, 4 shall take the first position 41 and in thatrespect form the previous mentioned stop or limiting means 27. Further,the guding means 70 shows a recess 47, in which the wedge 64 is arrangedto extend, and a holding element 48 for the locking element 40.

The wedge 64 and the guiding means 70 are fixed arranged in the first,lower body 2, whereby when the first, lower body reaches a resistance ora load 36, 37 the second, upper body 4 will approach the first, lowerbody 2 and when the upper body 4 strikes against the lower body 2 thelocking element 40 will be situated in front of the second opening 16 inthe upper body 4 and the wedge 64 will force and hold the lockingelement 40 against the seat in the second opening 16. When the second,upper body 4 reaches a resistance or a load 61 the first, lower body 2will approach the upper body 4 and the wedge 64 with the locking element40 will approach the second opening 16 in the upper body 4 and the wedgewith the wedge-shaped end portion 50 will force the locking element 40in the direction towards the seat in the second opening 16 and when thelower body 2 connects the the upper body 4, whereby the locking element40 is in front of the second opening 16, hold the locking element 40against the seat in the opening 16. The two bodies 2, 4 are by thatlocked and prevent a relative unintentional axial displacement with eachother. Such a locking device 44 can replace the locking device 44, whichappears from for example FIGS. 6, 11-17, 20, 22 and 26 and is morecomplicated.

Such a modified locking device 44 comprises the wedge 64, the lockingelement 40, a seat in a body 2, 4, which seat according to theembodiments consists of the second opening 16 in the second, upper body4, and the guiding means 70 which, however, also has other functionsthan to form a holder 45 for the locking element 40, as previous hasbeen mentioned. Besides what has previously been clear, there are noneed of i.a. the first guiding or limiting device 39 in a second object32 or according to the embodiment in the supporting stand 35 and with anupper end surface for influence on the second guiding or limiting device54 showing the projecting engagement part 55, which is not eitherneeded. Further, there are not either any need of limiting devices forthe wedge, as the stop 58 with the elastic element 57 for the functionof the wedge and the bottom or supporting element 56 for the elasticelement 57 and the stop 58, as the wedge is fixed arranged in a body. Inaddition, one avoids the complicated operation and dependence of theinfluence on the wedge or the engagement part 55 of the movable wedge 46of the second object 32 or supporting stand 35 and dependence of theelastic element 57. The operation of the locking device is in themodified locking device dependence of the bodies 2, 4 relative, axialposition with each other and displacement and appears from previousdescription. The positions and the displacement of the bodies 2, 4 arefundamental in the device 1 in accordance with the invention and thisfunction must still be ensured for the operation of device.

The locking device 44 can be held in the device 1 by a surrounding tubeor similar or according to the embodiment example by the first object 32or supporting stand 35.

When the method is used in connection with for example a supportingdevice 30 or a supporting stand 35, it is occurring that the supportingstand 35 or the device 1 is soiled, for example of dirt from the roadwayor the like, which normally have an injurious influence on a device orthreads of such an exposed object. The device 1 or screw 3 in accordancewith the invention is, however, self-cleaning by any collected dirt orthe like on screw 3 or spindle body 5 being removed when the device isused. When the screw 3 and bodies 2, 4 are engaged in the fine thread,and on movement between the screw and the bodies, the dirt will betransported to coarse thread 7 of screw 3, fall off or be scraped off bythreads or the said threaded spiral of bodies 2, 4, when screw 3 andbodies 2, 4 are engaged in the coarse thread.

Without exceeding the scope of the concept of the invention,modifications of the method and device in accordance with the inventionshould be possible. Thus, the method and device can, after constructiveadaptation if any, be used within a multiplicity different fields andfor a widely differing objects than the objects shown in the embodimentexamples concerning the supporting device and the extension andcontraction of a supporting stand. If it should be necessary and perhapswithin other fields of application to lock the bodies againstunintentional, relative axial displacement, when the bodies are engagedin the fine thread and in that respect in other positions than in astressed position with heavy loading, it ought to be possible to shapeand adapt the device for such an utilization. The guiding means can beshaped adjustable, whereby the said distance between the bodies shouldbe able to be adjusted or changed, as when other or more threads areutilizied. The said second guiding or limiting device with theengagement part can, as it has been appeared, be shaped in one piecewith the movable wedge. The shaping and constructive connection to thedevice of the exemplified supporting stand can be another. The methodand device is thus not restricted to what has been appeared from theembodiment examples but solely by the following claims.

We claim:
 1. A device for displacement of objects comprising a screwwith a spindle body and two bodies movable axially thereon, in which thescrew has two sets of threads with different pitches and the two bodiesare axially movable on said screw, each of said axially movable bodiesbeing selectively engageable with either of said sets of threads, andsaid axially movable bodies being axially displaceable relative to eachother.
 2. A device in accordance with claim 1, in which the said axiallymovable bodies are non-rotatable relative to each other, whereby thebodies can be selectively engaged with either of said sets of threads bychanging the distance between them.
 3. A device in accordance with claim1, having load-responsive means for causing each of said axially movablebodies to disengage one thread of said set and to engage the otherthread of said set when it encounters a predetermined load.
 4. A devicein accordance with claim 1, including locking means arranged to holdboth of said axially movable bodies in a predetermined relative axialposition.
 5. A device for displacement of objects comprising a screwwith a spindle body and at least one body movable axially thereon, inwhich the screw has two sets of threads with different pitches and themovable body is selectively engageable with either of said sets ofthreads, and having a load sensing means in said axially movable body,said load sensing means being engageable with one of said sets ofthreads and being releasable from said one set of threads uponencountering a predetermined load.